Apparatus for electrical precipitation



Aug. 26, 1930. w. DEUTSCH A-PRARATUS FOR ELECTRICAL PRECIPITATION FiledJuly 25, 1928 2 mu m. m w I f m Patented UNITED STATES PATENT". OFFICEWALTHER DEUTSCH, OI F BANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOB TO INTER-NATIONAL PRECIPITATION COMPANY, 01'! LOS ANGELES, CALIFORNIA, A CORPORA-'IION OF CALIFORNIA APPARATUS ron' nnnc'rnrcan rmzorrrra'r'ronApplication filed m 25, 1928, Serial no.

This invention relates to apparatus for the electrical precipitation ofsuspended particles from gases. The principal object of the invention isto provide for automatic shutting off of the gas flow through anelectrical precipitator upon failure or interruption of the currentsupplied to the electrodes thereof, so-

i that the possibility of unclean gas passing from the precipitator intothe atmosphere or" into subsequent apparatus of any sort, and aparticular object of the invention is to prevent this contingency fromarising. An example of such a case is in the removal of' arsenic fromthe gases before entering the contact chamber in the contact process ofsulphurlc acid manufacture, since if the gases were'permitted to entersuch contact chamher while still containing appreciable quantities ofarsenic, the catalytic substance in thechamber would, as is well known,beeffected in a deleterious manner.

With this object .in view the apparatus of my invention comprisesessentially an electrical precipitator, an electric circuit forsupplying current thereto, means for passing gas therethrough,dampermeans for cutting off the flow of such gas, and means operableupon cessation or undue decrease of current fiow 1n said circuit toclose said damper. The means for efie'cting automatic closing of thedamper.

may comprisefor example a relay coil or electromagnet connected in theenergizing circuito-f the precipitator, and means operable when thecurrent flow therethrough fallsbelow a certain amount to operate throughsuitable mechanism to cause closing of the damper. The damper may belocated either in the inlet or outlet flue of the electricalprecipitator.

The accompanying drawings illustrate an embodiment of my invention andreferring thereto. Fig. l'is-a partly diagrammaticside ele- 4 s vationof an electrical precipitator showing;

my invention applied thereto.

' Fig. 2 is an' enlarged rear view of part of the damper closingmechanism shown in Fig.1.,"

The electrical precipitator shownin the drawing comprises bottom header1, top head- 295,340, and in Germany August 20,1887.

er 2 and a plurality of pipes or tubes 3 ex I tending-between saidheaders and constitutmg the collecting electrode. Gas conducting flues 4and 5 are shown as connected to the lower and upper headers, one of saidflues serving as an inlet flue and the other as an outlet flue for thegases to be treated. Discharge electrode membersfi consisting forexample of wires or small rods are suspended Within the respective pipes3, as by means of a suitable supporting framework 7 mountalternatingcurrent at commercial voltage,

and a rectifyingdevice such as a mechanical rectifier consisting of arotating disc 14 of insulating material and provided in well knownmanner with two contact segments 15 and16adapted to contact with or topass in current transmitting relation with-four contact membersindicated at 17 "to 20. Two diametrically opposite contact members suchas 17 and 19 are connected to the secondary winding of transformer 12,said secondary winding being adapted to give the necessary high voltagefor operation of the precipita tor, for example 30,000 to 75,000 voltsor more. One of the intermediate contacts such as 18 is connected bywire 23 to some part of the discharge electrode system, for example to apart of the supporting frame 7 I as shown, while the other contact 20 isconnected by wire 24 to the collecting electrode 4 system,-said wirebeing preferably grounded as indicated at 25 so as to ground the col--lecting electrodes and also the contact 20 'of the rectifier. Includedin the wire 24 is a .relay coil or .electromagnet 26, which is adaptedas hereinafter described a to cause closing of the damper when thecurrent flow therethrough ceases or falls below a certain value.

The electrical precipitator and energizing circuit therefor abovedescribed are already well known and the details thereof form n0essential part of the invention. The invention is equally applicable toany other form of electrical precipitating apparatus, and other forms ofenergizing circuit may also be used.

A damper may be provided in either, of the flues 4 or 5. Two arms 31 and32 are shown as connected to the shaft of said damper, the end of arm 31being connected to a cable 33 passing over winding drum 34' which isprovided with a crank orhandle 35 whereby the damper may be manuallymoved to open position as shown. The winding drum 34 is provided with aratchet member 36 and a pawl or catch member 37 is pivoted at 38 and isnormally held by spring 39 in engagement with the teeth of said ratchet;

member. Upon the end of arm 32 is hung a suitable weight member 41 whichmay be. provided with a projecting arm 42. said weight member beingoperable to move the damper to closed position 11 on movement of pawlmember 37 out of e gagement with ratchet 36.

Suitable means are provided for causing such release of pawLmember 37upon deenergization of electromagnet 26. 7 Such means may comprise anelectromagnet 44 adapted to attract an armature 45 on said pawl'member,and a switch controlled by electromagnet 26 and comprising for example afixed contact member 45 and a contact member 46 on arm 47, which ispivotally mounted at 48 and is provided with an arma-- ture 49 actedupon by electromagnet 46, whereby contact 46 is normally held out ofengagement with contact 45, a spring 51 being' provided for closing saidcontacts when the current flow 1n electromagnet 26 ceases or falls belowa certain value, for example below the current value corresponding tothe a proper operating voltage or potential between the electrodes ofthe precipitator. A suitable source of current, such as battery 53 isconnected to the relay switch comprising I contact members 45 and 46 andto electro- 'magnet 44 in series. Another pair of contact members 56 and57 are preferably included in the circuit, said contact members beingnormally held in closed position by means of leaf spring 58, but; one ofsaid members being mounted upon arm 59 adapted to be engaged by arm 42on weight member 41 when sa1d we1ght member ispermitted to'fall ashereinafter described.

- The. operation-of the above described'apparatus is as follows. So longas the supply of electric current to the precipitator is malnta'lned, orso long as the current flow therethrough remains above a certain value,

electromagnet 26 will beenergized sufficient- 1y to hold contact member46 out of engagement with contact 45 against the action of -s ring 51,and magnet 44 will, therefore, be

e-energized, permitting pawl 37 to remain in engagement with ratchet 36,so as'to hold damper 30 in any position to which it may be moved byoperation of crank 35. Upon off the flow or gas through the'precipitator.

As the weight member 41 drops, the arm 42 thereon engages arm 59 andcauses contact to 1 be broken-between contact members 56 and 57 thusopening the circuit and preventing the continued drawing of currentfrombattery 53.

As soon as the power PP 'y to the P cipitator is again established, thedamper may again be operated to open position, and

since the contact member 46will then be held by electromagnet 26 out ofengagement with contact 45, the pawl 37 will again be held by spring 39in engagement with ratchet 36.

It will of course be understood that many other arrangements may-besubstituted for] the specific form above described, for causing thedamper to close when the current in the .precipitator circuit decreasesbelow the predetermined value, this particular form being shown only byway of example.

- I claim:

1. In combination with an electrical precipitator and with an electriccircuit for supplying current thereto and means for passage of gastherethrough, a damper in said gas passage vmeans, and meansincluded insaid circuit and. operable upon a predetermined decrease in currentflow'insaid circuit to cause said damper closed position.

2'. In combination with an electrical p'recipitator and with an electriccircuit for supplying current thereto and means for passage of gastherethrough, a damper in said gas passage means, an electromagnetincluded in said circuit, and means controlled by said electromagnet andoperable when the current flow in said electromagnet falls to a certainpredetermined value to cause said therefor and means for passage of gastherethrough, a damper in said gas passage means,

catch means tending to hold said damper in to be moved to openpo'sitionand means for releasing said catch means when the current in saidciramass:

cuit falls to a certain value, said damper being automaticall movable toclosed position upon such're ease of said catch means.

4. In an electrical precipitator, the combination with a treaterchamber, an electrode system in said chamber, an electric circuit forsupplyin currentto said system and an inlet and out et flue for passinggas through t e said chamber, of means controlled by flow of current insaid circuit andoperable when said current falls to a predeterminedvalue to prevent the flow of gas through said chamber. a I

5. The combination with an electrical precipitator having an electriccircuit for sup-1 plying current thereto and means for the passage ofgas therethrough, of a damper in said gas passage means, means tendingto close said damper, a latch for normally retaining said damper in openposition, and means including an electromagnet in said electric circuitfor tripping said latch when the current supplied to said. precipitatorfalls to a certain predetermined value. v

In testimony whereof I havehereunto subscribed my name this 3d dayofJuly, 1928.

WALTHER DEUTSOH.

